Acoustic-optical call indicator panel having time delay release of the optical indicators



Dec. 29, 1964 G. CONFORZI 3,153,857

ACOUSTIC-OPTICAL CALL INDICATOR PANEL HAVING TIME DELAY RELEASE OF THE OPTICAL INDICATORS Filed Oct. 25. 1961 A FIG. 2

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United States Patent 3,163,857 ACOUSTIC-OPTICAL CALL INDICATOR PANEL HAViNG TIME DELAY RELEASE OF TIE OPTI- CAL INDICATORS Gaetano Conforzi, Via G. Mercalli 80, Rome, Italy Filed Oct. 23, 1961, Ser. No. 147,022 1 Claim. (Cl. 340-322) The invention relates to acoustic and optical bell system indicating panels as they are used in hotels, offices, hospitals and the like.

Bell systems wherein the bells may be operated from a plurality of places, as from the different rooms of a hotel, generally comprise an optical indicating panel whereon the ringing place may be seen. Such an indicating panel may be combined with a hell or vibrator to direct a persons attention to the indicating panel.

These indicating panels generally comprise as many relays as there are push buttons. Whenever a push button is operated, the associated relay will release a drop indicator which either serves as an optical indicating element or which operates a secondary circuit comprising an incandescent lamp to illuminate a number sign.

In known systems of this kind the relays have to be restored manually into their original position whenever they have been actuated. This however has several disadvantages. First, restoration requires a certain although short time which however may be important if there are very many places from which the relays may be operated. Further if the indicating panel has not been observed for a longer period then there may have been operated a considerable number of relays. The panel however does not indicate the sequence in which the various relays have been operated. It seems advisable to indicate only those calls which have occurred in a predetermined and not too long an interval ending with the moment of observation of the indicating panel.

Further in systems which are not used very frequently or which are used only intermittently it is not advisable to have a step-down transformer connected to the power supply permanently. A manual disconnection is not advisable because disconnecting might be forgotten.

The object of the invention is to avoid the disadvantages explained above. That is, in using the invention it will no longer be necessary to restore the relays manually and it will become possible to perceive the calls having arrived only recently.

According to the invention there is associated to each optical indicator of the entire panel a relay which respends without delay but which releases with delay. This relay puts the step-down transformer and the optical indicating device into operation immediately and disconnects them with an appreciable delay.

FIGS. 1 and 2 show two embodiments of the invention.

FIG. 1 shows a diagram of a bell system which for instance may be used in a hotel. This system is fed from a normal A.C. power supply. Each push button P to P 7 which may be located in the various rooms of a hotel is series connected with the winding S to S respectively of relays B to 3 respectively. All these circuits are connected in parallel and are all connected in series to a common call indicator C. Each relay has a T-formed armature having a contact bridge, two separate contacts b and b being provided opposite this contact bridge. By these pairs of contacts a small lamp L to L respectively is connected to the secondary winding of a step-down transformer T. The primary winding of this transformer is connected with its upper terminal to the left-hand power supply terminal S and with its lower terminal to the terminals b' of the relays.

Whenever in the circuit according to FIG. 1 any push button for instance the push button P is pressed a circuit will be completed extending from the left-hand terminal S through the acoustic call indicator C, the push button P and the winding S of the relay B to the right-hand power supply terminal S. As long as the push button P is operated the bell C will be traversed by current and thus this bell will indicate acoustically that the push button in one of the rooms is being pressed. Further the relay is excited .and completes by bridging its contacts b and b two different circuits. The first circuit extends from the left-hand terminal S through the primary wind-' ing of the step-down transformer to the contact b of the relay B and completes through the T-like armature of this relay to the right-hand terminal S. Therefore the transformer T is connected to the power supply as long as the tends from the upper terminal of the secondary winding of the transformer T through the lamp L to contact 5 of the relay B and through the armature of this relay and the contact B to the lower terminal of the secondary winding of the transformer. Thus the lamp L remains connected to the secondary winding of the transformer as long as the contacts b and b of the relay B will remain bridged. During the release delay time of the relay B;, the lamp L will indicate in which room the button has been pressed.

The embodiment according to FIG. 2 differs from that according to FIG. 1 by the fact that the call indicator C in FIG. 2 is supplied with energy from the transformer secondary rather than from the transformer primary as in FIG. 1, further by the fact that the lamps L to L in FIG. 2 are fed from a portion of the secondary voltage only, rather than from the entire secondary voltage as in FIG. 1, and by the fact that each of the push buttons P to P in FIG. 2 closes two parallel circuits, one circuit comprising the call indicator C and the other one comprising one of the relays B to B When in the circuit of FIG. 2 for instance the push button P will be pressed then a circuit will be completed extending fromthe left-hand terminal S through the primary winding of the transformer T, the connecting point m, the connecting point n, the contact a of the push but-.

will respond immediately and will bridge its contacts b 7 and b By the contact 1); and the T-like armature of the relay the lower terminal of the primary winding of the V transformer will be connected to the right-hand terminal of the power supply. Thereforethe transformer will remain excited when the push button P will be released. 7

By bridging the contact b and b by'the T-like armature of the relay B the lamp L will be connected to the tap of the secondary winding of the transformer and thus will radiate as long as the contacts and b will be bridged. Further by pressing the push button P also the acoustic call indicator C will be operated through the contacts a and a of the push button and through the contact bridge k and will be connected to the fullsecondary voltage.

Thus in the embodiment of FIG. 2 the bell C will ring only as long as the respective button will be pushed.- The lamp however will radiate until the delay interval of the relay will have expired.

The relays used in the embodiments of FIGS. 1 and 2 may be timing relays of the general type as they are used in stair wells of houses.

What I claim is:

An acoustic-optical call indicating system, comprising,

Patented Dec. 29, 1964 the number of which corresponds to a number of call sta-,

tions; 21 common acoustic call indicator; a step-down transformer for supplying current to the optical indicating devices; a push-button switch at each call station to operate the associated indicating device and the common acoustic call indicator; and a time-delay-release relay associated with each indicating device circuit so that its contact completes the circuit when the relay is energized, each relay energizing coil being arranged to be connected by the switch to a source of electrical energy; each circuit comprising a switch and the exciting windings of an associated relay being connected in parallel with all other 'such circuits, the plurality of the latter circuits being connected in series with the acoustic call indicator; and each such circuit closing two contacts, when actuated, for connecting the primary winding 'of the transformer to the 4 1 power supply and completing the secondary'circuit of the transformer. '5

References Cited by the Examiner UNITED STATES PATENTS 998,705 7/11 Manson 340322 1,781,497 11/30 Crago 317-141 X 2,262,650 11/41 Reagan et al. 340-327 2,643,168 6/53 Louthan 340-322 X 2,888,669 5/59 Thomas et al. 340326 2,912,685 11/59 Thomas 340-326 X 2,942,249 6/:60 Paull Q 340-312 3,017,623 1/62 Bishofberger 340-322 NEIL C. READ, Primary Examiner. ROBERT H. ROSE, Examiner. 

